Los Angeles is about 1.5 times bigger than Kansas City.

Kansas City (map shows its 145 named neighbourhoods; the area covers the whole city) is approximately 815 sq km, while Los Angeles (including the city proper only) is approximately 1,215 sq km, making Los Angeles 49% larger than Kansas City.
Tip: This to-scale comparison of Kansas City vs. Los Angeles uses the Mercator projection, which distorts the size of regions near the poles.
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